The Section of Flow & Image Cytometry is concerned with d quantitative flow cytometry as it relates to our regulatory needs. An interagency working group (FDA, NIH, CDC, NIST) has been formed and is working on a flouresence intensity standards initiative. The flow cytometry laboratory consists of two FACScans and a FACStar Plus, all of which are connected with ethernet using TCP/IP. There are three other FACScan and two FACSTAR flow cytometers within CBER; they all have some level of network capability. Together these laboratories make up the CBER/FDA flow cytometry consortium. The next area of data analysis in flow cytometry will consist of a comparison of cluster analysis programs. The major program concerns the etiology and pathogenesis of common and familial B cell lymphocytic leukemia (B-CLL). This has consisted of an evaluation of two and three color surface immunofluorescence, cell cycle analysis and sorting of B cells for PCR analysis of monoclonality. This latter activity is being undertaken as part of a linkage analysis study in familial B-CLL. It is designed to detect early preclinical CLL in third and fourth generation family members to facilitate the formal genetic linkage analysis. Presently, we use magnetic beads and/or sorting to enrich B cells. Oligomeric primers for V-region families (VH1 through VH6) are used for clonal evaluation. An NZB mouse colony has been established to evaluate a murine model of B-CLL. Image analysis is being carried out to examine the morphological heterogeneity of lymphocytes seen on conventionally prepared blood films as a function of time. A linkage analysis in an F1 backcross has been completed A protocol of loss of heterozygosity, comparitive genomic hybridization and linkage analysis is being prepared to develop a genetic model. The Section of Flow & Image Cytometry is concerned with d quantitative flow cytometry as it relates to our regulatory needs. An interagency working group (FDA, NIH, CDC, NIST) has been formed and is working on a flouresence intensity standards initiative. The flow cytometry laboratory consists of two FACScans and a FACStar Plus, all of which are connected with ethernet using TCP/IP. There are three other FACScan and two FACSTAR flow cytometers within CBER; they all have some level of network capability. Together these laboratories make up the CBER/FDA flow cytometry consortium. The next area of data analysis in flow cytometry will consist of a comparison of cluster analysis programs. The major program concerns the etiology and pathogenesis of common and familial B cell lymphocytic leukemia (B-CLL). This has consisted of an evaluation of two and three color surface immunofluorescence, cell cycle analysis and sorting of B cells for PCR analysis of monoclonality. This latter activity is being undertaken as part of a linkage analysis study in familial B-CLL. It is designed to detect early preclinical CLL in third and fourth generation family members to facilitate the formal genetic linkage analysis. Presently, we use magnetic beads and/or sorting to enrich B cells. Oligomeric primers for V-region families (VH1 through VH6) are used for clonal evaluation. An NZB mouse colony has been established to evaluate a murine model of B-CLL. Image analysis is being carried out to examine the morphological heterogeneity of lymphocytes seen on conventionally prepared blood films as a function of time. A linkage analysis in an F1 backcross has been completed A protocol of loss of heterozygosity, comparitive genomic hybridization and linkage analysis is being prepared to develop a genetic model.